Where Can I Buy Genuine Briggs And Stratton Lawnmower Diaphragm And Gaskets?

Where Can I Buy Genuine Briggs And Stratton Lawnmower Diaphragm And Gaskets?

The main problems that occur with gas/petrol lawnmowers are poor running, hunting and surging and startup problems.

There are many aftermarket parts available online and it can be difficult to work out what’s genuine and what isn’t.

In short, you can purchase genuine Briggs And Stratton Gaskets for your lawnmower servicing right here https://repairlawnmowersforprofit.com/recommended-products/lawnmower-gaskets-and-diaphragms/  or the recommended parts store.


All parts will be distributed by Briggs And Stratton.

( I only sell 100% genuine gaskets direct from Briggs And Stratton )

In this article, I’m going to list most of the commonly used lawnmower gaskets, plus tips and tricks on how to replace them.

I’ll also explain why many after-market parts should be avoided.

This article and all the gaskets listed are designed for use with Briggs And Stratton Sprint, Classic 350 375 and 450 Engines also the Quattro 40 4.5

In short, if your lawnmower looks like the one in this video from my youtube channel listed below these gasket sets will be correct.

Genuine Briggs And Stratton Diaphragm And Gasket Set

First, let’s take a look at the most commonly replaced diaphragm and gasket set.

I have repaired hundreds of lawnmowers and sold them for profit, many times a lawnmower only needs a diaphragm and gasket to solve any running issues!

Without a doubt, the most common gasket set that needs replacing is for the Briggs And Stratton 35 Classic Engine Carburettor.

If you have a lawnmower with the engine and carburettor shown in the above video, then here is where you can buy a genuine Briggs And Stratton gasket set.


You will need to replace the diaphragm and gasket if your lawnmower is stalling, hunting or surging.

A classic sign of an engine needing a new diaphragm and gasket set is an engine that revs up and down.

You can read more on hunting and surging problems in my article here (and why altering the governor springs won’t help!)


Why Buy Genuine Gaskets?

I have tried and tested many aftermarket parts over the years.

My conclusion is that some work fine but the majority cause more problems than you had to begin with.

Chances are you are reading this article as you are already having problems with your lawnmower.

Buying genuine spare gaskets (or any parts) is the only way to ensure that you are eliminating a problem and not adding to it.

I have seen aftermarket diaphragm and gasket sets last less than 30 seconds In Briggs And Stratton carburettors before the fuel supply is inefficient and the lawnmower stalls and dies.

On inspection of the gasket, there was barely anything left and what remained curled up into a ball!

Imagine purchasing a new lawnmower simply because your current one didn’t function properly using aftermarket parts!

All the Briggs And Stratton Classic engines as shown in the video above use this gasket set. https://repairlawnmowersforprofit.com/recommended-products/lawnmower-gaskets-and-diaphragms/

I will include a link to new governor springs here also as many times they have been tampered with and need replacing.


Replacing this diaphragm and gasket set on the classic Briggs And Stratton carburettor solves 90% of all running problems.

I have done this repair hundred of times!

The diaphragm and gasket are serviceable parts and replacing these gaskets along with damaged governor springs is the most common procedure I do when repairing any lawnmowers to sell on for profit.

Take a look at this playlist of videos from my Youtube channel on common lawnmower repairs.

Please subscribe to my Youtube channel here https://www.youtube.com/c/MowerMan

Other Briggs And Stratton Gaskets.

In the rest of this article, I’m going to discuss many other gaskets, springs, O rings and other parts I regularly replace on Briggs And Stratton Lawnmowers.

Some of these small inexpensive parts can make a huge difference to the running of your lawnmower.

Head Gasket

One of the more obvious items that may occasionally need replacing is the engine head gasket.

I like to remove the head of my own Briggs And Stratton engine occasionally and clean off all the carbon deposits. This stops old carbon transferring into the bore and over time causing wear.

With this carbon cleaned it’s a good idea to replace the head gasket. Be sure to clean off the cylinder head before replacing the engine head gasket.

The correct head gasket for a Briggs And Stratton Classic engine is Briggs and Stratton Genuine 698717 Cylinder Head Gasket

If you are looking to replace the head gasket on a Briggs Quantum engine take a look here. Briggs and Stratton Genuine 272200S Cylinder Head Gasket

Whilst head gaskets are not replaced too often I would recommend replacing it if the engine head has been removed on an engine over 5 years old.

O Rings

This part is massively important on the Classic Briggs Engine.

One common mistake I see is when the petrol tank and carburettor have been removed from the engine and then re-installed.

On the back of the intake manifold, there are 2 O rings. A black one (inlet seal) and a white one (retainer).

Many times these parts are not fitted correctly when re-fitting the carburettor and gas tank back onto the engine.

The correct way to do this is to push the black O ring in first, then the white retainer on the outer. (see above video)

Fit these parts onto the carburettor first.

Slide the carburettor onto the intake manifold evenly. If you have a leak here you will have terrible hunting and surging problems.

If you need to replace these O rings you can buy genuine ones here

Black O ring.
Seal ‘O’ Ring Briggs & Stratton Part No.270344S Genuine

White retainer

If you don’t have an airtight seal, you will have running problems similar to having a worn diaphragm and gasket.

Inlet Manifold Gasket

To replace the inlet manifold gasket you will need to remove the starter recoil and ignition. Check out this article to find out how to do this. https://repairlawnmowersforprofit.com/how-to-replace-the-ignition-coil-on-a-petrol-lawnmower/

There are various shapes and sizes of inlet manifold. The best option is to take a look at the shape of the one fitted and match it up with the genuine spares listed below.

It’s often easier to buy the manifold and gasket together to ensure you don’t purchase the wrong gasket!

Here is a list of genuine spares.

I have included both manifolds for the Classic Engine

Briggs and Stratton Genuine 693446 Intake Manifold

Briggs and Stratton Genuine 699644 Intake Manifold

Most times the inlet gasket will need replacing is when you purchase a lawnmower to sell on for profit that someone has taken to pieces and lost the part.

Air Filter Gasket

The easiest gasket to lose is the one that sits on top of the carburettor between the air filter box and the carburettor itself.

This gasket tends to stick to the underside of the air filter box and get lost!

You will need to replace this to provide a good seal between the air filter and carburettor on a Briggs Classic Engine.

It is essential that the carburettor receives the correct airflow to run correctly.

Here is where you can find a genuine replacement air filter gasket. Air Cleaner Gasket For Briggs & Stratton 271139, 271139S by Rotary for Briggs & Stratton

I have also included a link to a genuine air filter.Briggs & Stratton 698369 Yellow Foam Air Filter. Classic, Sprint & Quattro Engine, 1

Exhaust Gasket

Most lawnmowers have an exhaust guard fitted and it is often the case that you the guard is fitted in conjunction with the starter recoil assembly.

To remove the guard you will need to remove the starter recoil. You can see how to do this by watching one of my youtube videos from my own youtube channel.


With the exhaust guard removed, you will be able to remove the exhaust and replace the gasket if necessary.

The correct exhaust gasket is Briggs & Stratton 691893 Exhaust Gasket Replacement for Models 273348, 691893 and 557047

There are 2 different exhaust types fitted to Briggs And Stratton engines, a round and a rectangular shaped one.

For reference, the rectangular one that bolts to the engine is much quieter in operation than the round one!


A grommet is a small rubber 90 -degree rubber part that connects aluminium breather tube to the carburettor.

This small part is also often re-fitted incorrectly when a carburettor has been re-assembled.

Take care when fitting this part and be sure to keep an eye on it when tightening the gas tank back onto the lawnmower.

The correct genuine spare can be located here. Genuine Briggs & Stratton Carb Grommet fits Classic & Sprint Engines Part 692189

Don’t be tempted to purchase aftermarket grommets or primer bulbs, although they may seem insignificant small parts often or the rubber is poor quality and will perish or split in no time in cold conditions or when left in the sun for long periods.

Genuine parts are built with these parameters in mind.

Crankcase Gasket

There are 2 types of crankcase gaskets on these Briggs And Stratton engines.

The crankcase should only be opened in extreme situations. It’s not something I get involved with whilst repairing lawnmowers for profit.

The first crankcase gasket has 6 bolts retaining the sump. BRIGGS AND STRATTON 692218 GASKET-CRKCSE/015

The second crankcase gasket has 7 screws that retain the sump. Briggs & Stratton 799587 Crankcase Gasket

Complete Gasket Sets

It is possible to purchase a complete gasket set for particular lawnmowers.

This would be useful if you are giving the engine a complete overhaul.

If a lawnmower has been sat for many years without use, particularly in cold conditions then replacing all the gaskets would be advisable.

Occasionally I pick up lawnmowers that have been stored for over 20 years to restore and repair for profit.

On these occasions, I usually purchase a new complete set of gaskets for that lawnmower.

Here is a complete set of gaskets.Briggs & Stratton 590777 Engine Gasket Set Replaces 794209, 699933, 298989 by Magneto Power

Take a look at the recommended parts page for all other items you may require. Feel free to leave me a comment on my youtube channel if you can’t find a particular part


Happy Mowing

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